package org.apache.maven.plugin.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.concurrent.atomic.AtomicReference;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.plugin.LegacySupport;
import org.codehaus.plexus.component.annotations.Component;
import org.eclipse.aether.RepositorySystemSession;

/**
 * Helps to provide backward-compatibility with plugins that use legacy components.
 * <strong>Warning:</strong> This is an internal utility component that is only public for technical
 * reasons, it is not part of the public API. In particular, this component can be changed or
 * deleted without prior notice.
 * 
 * @since 3.0
 * @author Benjamin Bentmann
 */
@Component(role = LegacySupport.class)
public class DefaultLegacySupport implements LegacySupport {

  private static final ThreadLocal<AtomicReference<MavenSession>> SESSION = new InheritableThreadLocal<AtomicReference<MavenSession>>();

  public void setSession(MavenSession session) {
    AtomicReference<MavenSession> reference = DefaultLegacySupport.SESSION.get();
    if (reference != null) {
      reference.set(null);
    }

    if (session == null && reference != null) {
      DefaultLegacySupport.SESSION.remove();
    } else {
      DefaultLegacySupport.SESSION.set(new AtomicReference<MavenSession>(session));
    }
  }

  public MavenSession getSession() {
    AtomicReference<MavenSession> currentSession = DefaultLegacySupport.SESSION.get();
    return currentSession != null ? currentSession.get() : null;
  }

  public RepositorySystemSession getRepositorySession() {
    MavenSession session = getSession();
    return (session != null) ? session.getRepositorySession() : null;
  }

}
